1. Field of the Invention
The invention relates to a control device for switching intake and exhaust valves of internal combustion engines, wherein the control device comprises a control valve with a control valve piston by which the supply of hydraulic medium from a pressure line to the intake or exhaust valve can be controlled.
2. Description of the Related Art
Camshafts are conventionally used for switching or controlling intake or exhaust valves of internal combustion engines. It is also known to hydraulically control the intake or exhaust valves. The hydraulic medium which is supplied by a pressure line is supplied via the control valve piston to the intake or exhaust valves which are then moved into the required position by the pressurized hydraulic medium.
It is an object of the present invention to configure the control device of the aforementioned kind such that the intake or exhaust valves can be adjusted optimally.
In accordance with the present invention, this is achieved in that the intake or exhaust valve has at least one actuating element which has at least one damping device at its side facing away from the hydraulic medium wherein the damping device counteracts the force exerted by the hydraulic medium onto the actuating element.
In the control device according to the present invention the hydraulic damping can be adjusted such that it conforms to the activation curve of the cam of a camshaft. In this way, it is possible to provide harmonic transitions, as they are known from camshafts, even for camshaft-free internal combustion engines in a simple way and with significant advantages in comparison to conventionally controlled engines.